Utilities

Utilities — Various utility routines

Functions

Types and Values

Description

Various utility routines.

Functions

udisks_decode_udev_string ()

gchar *
udisks_decode_udev_string (const gchar *str,
                           const gchar *fallback_str);

Unescapes sequences like \x20 to " " and ensures the returned string is valid UTF-8.

If the string is not valid UTF-8, try as hard as possible to convert to UTF-8.

If NULL is passed, then NULL is returned.

See udev_util_encode_string() in libudev/libudev-util.c in the udev tree for what kinds of strings can be used.

Parameters

str

An udev-encoded string or NULL.

 

fallback_str

String to use when str can't be converted to a valid UTF-8 string.

 

Returns

A valid UTF-8 string that must be freed with g_free().


udisks_safe_append_to_object_path ()

void
udisks_safe_append_to_object_path (GString *str,
                                   const gchar *s);

Appends s to str in a way such that only characters that can be used in a D-Bus object path will be used. E.g. a character not in A-Z[0-9]_ will be escaped as _HEX where HEX is a two-digit hexadecimal number.

Note that his mapping is not bijective - e.g. you cannot go back to the original string.

Parameters

str

A GString to append to.

 

s

A UTF-8 string.

 

udisks_daemon_util_block_get_size ()

guint64
udisks_daemon_util_block_get_size (GUdevDevice *device,
                                   gboolean *out_media_available,
                                   gboolean *out_media_change_detected);

Gets the size of the device top-level block device, checking for media in the process

Parameters

device

A GUdevDevice for a top-level block device.

 

out_media_available

Return location for whether media is available or NULL.

[out]

out_media_change_detected

Return location for whether media change is detected or NULL.

[out]

Returns

The size of device or 0 if no media is available or if unknown.


udisks_daemon_util_resolve_link ()

gchar *
udisks_daemon_util_resolve_link (const gchar *path,
                                 const gchar *name);

Resolves the symlink path /name .

Parameters

path

A path

 

name

Name of a symlink in path .

 

Returns

A canonicalized absolute pathname or NULL if the symlink could not be resolved. Free with g_free().


udisks_daemon_util_resolve_links ()

gchar **
udisks_daemon_util_resolve_links (const gchar *path,
                                  const gchar *dir_name);

Resolves all symlinks in path /dir_name . This can be used to easily walk e.g. holders or slaves of block devices.

Parameters

path

A path

 

dir_name

Name of a directory in path holding symlinks.

 

Returns

An array of canonicalized absolute pathnames. Free with g_strfreev().


udisks_daemon_util_check_authorization_sync ()

gboolean
udisks_daemon_util_check_authorization_sync
                               (UDisksDaemon *daemon,
                                UDisksObject *object,
                                const gchar *action_id,
                                GVariant *options,
                                const gchar *message,
                                GDBusMethodInvocation *invocation);

Checks if the caller represented by invocation is authorized for the action identified by action_id , optionally displaying message if authentication is needed. Additionally, if the caller is not authorized, the appropriate error is already returned to the caller via invocation .

The calling thread is blocked for the duration of the authorization check which could be a very long time since it may involve presenting an authentication dialog and having a human user use it. If auth.no_user_interaction in options is TRUE no authentication dialog will be presented and the check is not expected to take a long time.

See Table 1, “Known polkit variables” for the variables that can be used in message but note that not all variables can be used in all checks. For example, any check involving a UDisksDrive or a UDisksBlock object can safely include the fragment

$(drive) since it will always expand to the name of

the drive, e.g. INTEL SSDSA2MH080G1GC (/dev/sda1) or the block device file e.g. /dev/vg_lucifer/lv_root or /dev/sda1. However this won't work for operations that isn't on a drive or block device, for example calls on the

Manager

object.

Parameters

daemon

A UDisksDaemon.

 

object

The GDBusObject that the call is on or NULL.

[allow-none]

action_id

The action id to check for.

 

options

A GVariant to check for the auth.no_user_interaction option or NULL.

[allow-none]

message

The message to convey (use N_).

 

invocation

The invocation to check for.

 

Returns

TRUE if caller is authorized, FALSE if not.


udisks_daemon_util_get_caller_uid_sync ()

gboolean
udisks_daemon_util_get_caller_uid_sync
                               (UDisksDaemon *daemon,
                                GDBusMethodInvocation *invocation,
                                GCancellable *cancellable,
                                uid_t *out_uid,
                                GError **error);

Gets the UNIX user id of the peer represented by invocation .

Parameters

daemon

A UDisksDaemon.

 

invocation

A GDBusMethodInvocation.

 

cancellable

A GCancellable or NULL.

[allow-none]

out_uid

Return location for resolved uid or NULL.

[out]

error

Return location for error.

 

Returns

TRUE if the user id (and possibly group id) was obtained, FALSE otherwise


udisks_daemon_util_get_caller_pid_sync ()

gboolean
udisks_daemon_util_get_caller_pid_sync
                               (UDisksDaemon *daemon,
                                GDBusMethodInvocation *invocation,
                                GCancellable *cancellable,
                                pid_t *out_pid,
                                GError **error);

Gets the UNIX process id of the peer represented by invocation .

Parameters

daemon

A UDisksDaemon.

 

invocation

A GDBusMethodInvocation.

 

cancellable

A GCancellable or NULL.

[allow-none]

out_pid

Return location for resolved pid or NULL.

[out]

error

Return location for error.

 

Returns

TRUE if the process id was obtained, FALSE otherwise


udisks_daemon_util_setup_by_user ()

gboolean
udisks_daemon_util_setup_by_user (UDisksDaemon *daemon,
                                  UDisksObject *object,
                                  uid_t user);

Checks whether the device represented by object (if any) has been setup by user .

Parameters

daemon

A UDisksDaemon.

 

object

The GDBusObject that the call is on or NULL.

 

user

The user in question.

 

Returns

TRUE if object has been set-up by user , FALSE if not.


udisks_daemon_util_dup_object ()

gpointer
udisks_daemon_util_dup_object (gpointer interface_,
                               GError **error);

Gets the enclosing UDisksObject for interface , if any.

Parameters

interface_

A GDBusInterface-derived instance.

[type GDBusInterface]

error

NULL, or an unset GError to set if the return value is NULL.

 

Returns

Either NULL or a UDisksObject-derived instance that must be released with g_object_unref().

[transfer full][type UDisksObject]


udisks_daemon_util_inhibit_system_sync ()

UDisksInhibitCookie *
udisks_daemon_util_inhibit_system_sync
                               (const gchar *reason);

Tries to inhibit the system.

Right now only

systemd

inhibitors are supported but other inhibitors can be added in the future.

Parameters

reason

A human readable explanation of why the system is being inhibited.

 

Returns

A cookie that can be used with udisks_daemon_util_uninhibit_system_sync().


udisks_daemon_util_uninhibit_system_sync ()

void
udisks_daemon_util_uninhibit_system_sync
                               (UDisksInhibitCookie *cookie);

Does nothing if cookie is NULL, otherwise uninhibits.

Parameters

cookie

NULL or a cookie obtained from udisks_daemon_util_inhibit_system_sync().

 

udisks_daemon_util_hexdump ()

gchar *
udisks_daemon_util_hexdump (gconstpointer data,
                            gsize len);

Utility function to generate a hexadecimal representation of len bytes of data .

Parameters

data

Pointer to data.

 

len

Length of data.

 

Returns

A multi-line string. Free with g_free() when done using it.


udisks_daemon_util_hexdump_debug ()

void
udisks_daemon_util_hexdump_debug (gconstpointer data,
                                  gsize len);

Utility function to dumps the hexadecimal representation of len bytes of data generated with udisks_daemon_util_hexdump() using udisks_debug().

Parameters

data

Pointer to data.

 

len

Length of data.

 

udisks_daemon_util_file_set_contents ()

gboolean
udisks_daemon_util_file_set_contents (const gchar *filename,
                                      const gchar *contents,
                                      gssize contents_len,
                                      gint mode_for_new_file,
                                      GError **error);

Like g_file_set_contents() but preserves the mode of the file if it already exists and sets it to mode_for_new_file otherwise.

Parameters

filename

Name of a file to write contents to, in the GLib file name encoding.

[type filename]

contents

String to write to the file.

[array length=length][element-type guint8]

contents_len

Length of contents , or -1 if contents is a NUL-terminated string.

 

mode_for_new_file

Mode for new file.

 

error

Return location for a GError, or NULL.

 

Returns

TRUE on success, FALSE if an error occurred


udisks_daemon_util_on_user_seat ()

gboolean
udisks_daemon_util_on_user_seat (UDisksDaemon *daemon,
                                 UDisksObject *object,
                                 uid_t user);

Checks whether the device represented by object (if any) is plugged into a seat where the caller represented by user is logged in and active.

This works if object is a drive or a block object.

Parameters

daemon

A UDisksDaemon.

 

object

The GDBusObject that the call is on or NULL.

 

user

The user to check for.

 

Returns

TRUE if object is on the same seat as one of user 's active sessions, FALSE otherwise.


udisks_daemon_util_get_free_mdraid_device ()

gchar *
udisks_daemon_util_get_free_mdraid_device
                               (void);

Gets a free MD RAID device.

Returns

A string of the form "/dev/mdNNN" that should be freed with g_free() or NULL if no free device is available.


udisks_ata_identify_get_word ()

guint16
udisks_ata_identify_get_word (const guchar *identify_data,
                              guint word_number);

Gets a word from position word_number from identify_data .

Parameters

identify_data

A 512-byte array containing ATA IDENTIFY or ATA IDENTIFY PACKET DEVICE data or NULL.

[allow-none]

word_number

The word number to get - must be less than 256.

 

Returns

The word at the specified position or 0 if identify_data is NULL.


udisks_daemon_util_trigger_uevent ()

void
udisks_daemon_util_trigger_uevent (UDisksDaemon *daemon,
                                   const gchar *device_file,
                                   const gchar *sysfs_path);

Triggers a 'change' uevent in the kernel.

The sysfs_path takes precedence if non-NULL over a device_file . In case of using device_file any symlinks are resolved, this expects the block device has been processed by udev already.

The triggered event will bubble up from the kernel through the udev stack and will eventually be received by the udisks daemon process itself. This method does not wait for the event to be received.

Parameters

daemon

A UDisksDaemon.

 

device_file

Block device file (/dev/xxx) or NULL.

 

sysfs_path

Device path in /sys or NULL.

 

udisks_daemon_util_trigger_uevent_sync ()

gboolean
udisks_daemon_util_trigger_uevent_sync
                               (UDisksDaemon *daemon,
                                const gchar *device_file,
                                const gchar *sysfs_path,
                                guint timeout_seconds);

Triggers a 'change' uevent in the kernel and waits until it's received and processed by udisks.

The sysfs_path takes precedence if non-NULL over a device_file . In case of using device_file any symlinks are resolved, this expects the block device has been processed by udev already.

Unlike udisks_daemon_util_trigger_uevent() that just triggers a synthetic uevent to the kernel, this call will actually block and wait until the UDisksLinuxProvider receives the uevent, performs probing and processes the uevent further down the UDisks object stack. Upon returning from this function call the caller may assume the event has been fully processed, all D-Bus objects are updated and settled. Typically used in busy wait for a particular D-Bus interface.

Note that this uses synthetic uevent tagging and only works on linux kernel 4.13 and higher. In case an older kernel is detected this acts like the classic udisks_daemon_util_trigger_uevent() call and FALSE is returned.

Parameters

daemon

A UDisksDaemon.

 

device_file

Block device file (/dev/xxx) or NULL.

 

sysfs_path

Device path in /sys or NULL.

 

timeout_seconds

Maximum time to wait for the uevent (in seconds).

 

Returns

TRUE if the uevent has been successfully received, FALSE otherwise or when the kernel version is too old.


udisks_module_validate_name ()

gboolean
udisks_module_validate_name (const gchar *module_name);

Checks the string for a valid udisks2 module name. Only alphanumeric characters along with the '-' and '_' separators are permitted.

Parameters

module_name

A udisks2 module name.

 

Returns

TRUE if the string is a valid udisks2 module name, FALSE otherwise.

Types and Values

UDisksInhibitCookie

typedef struct UDisksInhibitCookie UDisksInhibitCookie;

Opaque data structure used in udisks_daemon_util_inhibit_system_sync() and udisks_daemon_util_uninhibit_system_sync().